The disclosure generally relates to fluorescence imaging, and more particularly relates to a nonlinear fluorescence imaging system and method employing optical fibers.
Nonlinear fluorescence imaging is a powerful imaging modality offering unique characteristics that can provide useful imaging information. Nonlinear fluorescence is generally achieved where laser pulses generated by a pulsed laser excite fluorescence in a target sample. The nonlinear fluorescence intensity is detected and processed to acquire imaging information. Nonlinear fluorescence imaging may be particularly useful for microscopy and endoscopy. Nonlinear microscopy includes intrinsic optical sectioning ability due to nonlinear excitation process, deeper penetration depth into tissue because of the excitation light, and reduced photobleaching and phototoxicity in the out-of-focus regions due to the general confinement of fluorescence excitation to the focal region.
Proposed fluorescence imaging systems typically use complicated pulsed lasers and bulk optics. Some proposed imaging systems may employ fiber optics, however, conventional optical fiber based imaging systems typically suffer from degradation of the laser pulses due to nonlinear effects in the optical fiber which limits the imaging resolution, depth and speed. In addition, because of the tradeoff between the image depth and the scanning speed, typically only one parameter is optimized in proposed systems.